Trucks, such as those that trail tanks, use hydraulic fluid to perform work such as running hydraulic motors on the truck to convey material. As the hydraulic fluid performs work, the fluid heats up. To cool the fluid and to keep it from overheating, a truck will have a mobile hydraulic fluid cooling assembly. The assembly will usually be mounted on the frame rail of the truck.
A known cooling assembly includes a heat exchanger; a fan; a fan motor coupled to the fan; a hydraulic fluid reservoir; a hydraulic fluid filter; and hydraulic fluid conduits. The conduits typically include flexible hoses and fittings to couple the hoses as needed to the heat exchanger; filter and control block. If the fan motor is hydraulically driven, some of the hoses would be coupled to the fan motor by fittings. The assembly, in connection with the heat exchanger and other structure of the assembly, forms an air-box into which air is drawn by the fan through the heat exchanger and exhausted from the air-box to atmosphere. The assembly also includes structure to carry the above items and mount the above items to the truck frame rail.
In operation a known cooling assembly, as described above with a hydraulic fan motor, generally operates as follows. The fluid, after it performs work, now called low pressure fluid is routed, by way of a return conduit into the control block. The return conduit which can include a hose and fitting, is connected to the control block by the fitting. The fitting is coupled to the block at a return port opening into the block. The fluid from the control block passes into the heat exchanger. A hose forms part of the passage. As the fluid passes through the heat exchanger, it is cooled by air being drawn through the heat exchanger into the air-box by the fan. The air is exhausted from the air-box by the fan to atmosphere. The fluid, after it exits the heat exchanger enters a hose. Downstream of the hose is a filter which receives the fluid after it has passed through the hose. The fluid passes through the filter. After the fluid passes through the filter it is emptied into the reservoir. From the fluid reservoir, fluid is drawn out of the reservoir by a pump. The fluid is drawn into the pump and is then again pressurized by the pump to perform work. The fluid, after it performs work, is then recirculated, as described above, through the heat exchanger and back to the reservoir.
Some of the fluid as it is pressurized by the pump, but before it performs work, is routed to the hydraulic fan motor. A bypass conduit routes the fluid, high pressure fluid, from a high pressure line, to the control block. Downstream of the control block, the fluid is routed through a hose into the fan motor. The fluid exits the fan motor. After the fluid exits the fan motor it enters a hose. After it exits the hose it enters the filter. After the fluid passes through the filter, it is emptied into the reservoir.